1. Field of the Invention
This invention relates to improvements in trailer structures; and, more particularly, to improved structural members. Still more particularly, the invention relates to improvements in trailers utilized for utility loads including wheel-supported loads.
2. State of the Prior Art
The use of utility trailers to transport all terrain vehicles (ATV""s), riding lawn equipment, riding golf carts, and other wheel-supported loads are known. These include wheel-supported loads having two, three, four, or more wheels as well as wheel driven track systems. Various ramp devices have been developed to aid in the loading of such wheel-supported loads from the ground surface to the bed of the trailer. It has long been recognized that wheel-supported loads having aligned wheels and those having four or more wheels arranged in tandem pairs can be difficult or impossible to load if the ramp structure is too short and the angle of the ramp to the trailer bed is great enough for the wheel-supported load to engage the juncture of the ramp and the bed causing the leading wheels to fail to contact the surface of the bed. This high centering results in the load not being supported by one or more of its wheels. This phenomenon is particularly apparent in vehicles such as riding lawn mowers when the mowing deck is suspended between the wheels, ATVs, golf carts, and the like.
In fixed bed utility trailers, the problem of high centering loads has been addressed by making the ramp structure longer and longer to minimize the angle at which the ramp affixes to the trailer bed.
It is known in the prior art to provide a loading ramp that is hingedly mounted to a utility trailer bed and is operable to be raised forming an extended end gate when the trailer is in motion. Various types of hinged ramps have been developed, and have utilized various types of structural materials. The ramp structures of course had to be of sufficient strength to support the loads and had to be constructed to allow sufficient traction for wheel driven loads to move up the ramp. Solutions involving wooden structures were heavy, and required either some form of nonskid surfacing or cross cleats to engage the wheel driven load.
A common type of prior art ramp involves the use of meshed metal sheets supported on a sufficiently strong frame to support the load. In all cases the hinge mounted extended loading ramps are heavy and unwieldy to handle. They also cause an extensive wind drag when being towed due to the fact that they present a substantial surface that can extend five or more feet above the surface of the trailer bed.
It is desirable to provide a loading structure that minimizes the amount of material used in the loading ramp to minimize the cost of construction and maximize the ease of use. It is also desirable to provide a loading ramp structure that minimizes the air drag with its attendant loss of fuel efficiency for the towing vehicle, while providing positive traction for wheel driven loads.
Tilt-bed trailers were developed to assist moving loads from a ground surface to the trailer bed by causing the bed to tilt such that a loading edge would engage the ground surface. As a wheel-supported load is moved from the ground surface onto the trailer bed, the bed is allowed to rotate back into contact with the tongue such that the bed can be affixed to the tongue and the load moved. The prior art tilt-bed trailers work reasonably well where the length of the tilt-bed is sufficiently long to allow the angle of the bed to the ground surface to be relatively small. For short bed utility trailers with a tilt-bed, the problem is often encountered that the leading structure of the load impinges on the tilted bed at a point that inhibits the wheels from being allowed to come in contact with the trailer bed. A further problem exists, particularly with riding lawn mowers and the like, of a trailing structure engaging the ground surface as the load is moved onto the bed such that the rear wheels are lifted from contact with the ground or the trailer bed. Of course these conditions exist in reverse when the load is to be removed from the trailer bed to the ground surface.
The shorter tilt-bed trailers have the additional concern that the angle of loading is relatively steep. If care is not taken when moving the wheeled load onto the bed, the weight distribution can go past the balance point too quickly and cause the trailer bed to rotate sharply to the level position thereby causing a substantial jolt when the bed impacts the tongue. If the wheel-supported vehicle is ridden onto the trailer by a human operator, such a jolting action is uncomfortable and in some instances can cause injury.
It is desirable to provide an improved structure for use with tilt-bed utility trailers that minimizes the deficiencies and undesirable features of prior art tilt-bed trailers.
The present invention includes a lightweight aluminum trailer frame structure for use with a tilt-bed trailer and having a tilt limiting loading ramp coupled to the frame. The tilt limiting loading ramp includes a tilt limiting structure to engage the ground when the frame is tilted for loading, the range of tilt limitation being such that a trailer bed supported on the frame is substantially aligned with the ramp. The tilt limiting loading ramp is constructed of members arranged across the width of the trailer bed and spaced apart a sufficient distance to minimize wind drag when raised and the trailer is being towed, but close enough to prevent the wheels of a wheel supported load from passing between them as the load is being moved onto the trailer bed. The arrangement is such that the height of the tilt limiting loading ramp as it relates to the height of the tilt limiting structure establishes a predetermined ratio for establishing the slope of the ramp. This ratio is selected depending upon the length of the trailer bed to establish the desired alignment between the bed and the ramp.
Another aspect of the invention is an improved side structural member constructed of extruded non-corrosive metal, with one such member utilized at each side of a trailer bed frame. Each side structural member is cut to a predetermined length to establish the desired length of the trailer bed and includes a number of functional features in addition to providing frame structure. The side structural member includes an upper portion extending upwardly from the bed surface and has an upper channel for providing strength to the side structural member and for cooperating in mounting auxiliary fixtures. A face member extends downwardly from the upper portion and has a lower extremity. The face portion has an inner surface to which is integrally formed an elongated retention channel extending along the length of the side structural member. This retention channel functions in cooperation with slidably positionable tie-down loops to allow loads to be cross-tied between the oppositely disposed side structural members. Such cross tying is particularly beneficial for wheel-supported loads. The integrally formed retention channel is also used for mounting an auxiliary rack to the trailer structure. In addition to the upper portion, the face portion, and the integrally formed retention channel, an axle mounting and positioning structure can also be utilized. In such an additional configuration, an inner member is integrally formed and downwardly extending from the elongated retention channel and having a lower extremity. A lower channel structure is integrally formed and coupled to the lower extremity of the face portion and the lower extremity of the inner portion. The lower channel structure has a downward channel opening and a predetermined shape including a mounting structure having oppositely disposed ridge mounting surfaces. The lower channel structure is adapted for use in combination with a mating slidable axle support member that has a predetermined length and one or more threaded holes therethrough to mate with and slidably engage the oppositely disposed ridged mounting surfaces. This structure allows a supported axle to be moved to a predetermined desired position along the length of the side structural member and to be clamped in place when mounting bolts are tightened.
An improved fender mounting bracket for use with a low profile trailer with the bed mounted low between the wheels is provided. The fender bracket includes an upper portion to be gripped by the upper channel of the side structural member, a middle portion to which are affixed outwardly extending mounting structures, and a lower portion to be held in place in cooperation with an associated slidable axle support member. The mounting structures are outwardly extending and each include a longitudinal nut retention channel to allow one or more bolts through an associated fender to be tightened to associated captive nuts held within the channel. The mounting structures can also be utilized as support for steps at the front and the rear of a fender to allow an operator to step up onto the trailer structure.
Another aspect of the invention for low profile tilt-bed trailers is a hitch level adapter selected to have a height to maintain a trailer tongue at a predetermined level when hitched to a towing vehicle. A trailer tongue having oppositely disposed ridges along at least a portion of its length is rotatably coupled to the tilt-bed trailer frame structure. The hitch adapter includes an upper box beam structure having an upper surface for mounting a trailer hitch. A pair of downwardly extending oppositely disposed gripping members are provided to cooperate with and grip the ridges on the trailer tongue. Bolts through the downwardly extending members and the trailer tongue hold the hitch adapter firmly in place.
An improved tilt-bed trailer has supporting means for supporting trailer bed means with such supporting means including side structural means for mounting a wheel assembly. Bed means are mounted on the supporting means for supporting a load. Tongue means are rotatably coupled to the supporting means for allowing the trailer to be towed, and for allowing the supporting means to rotate the bed means with respect to the tongue means. Tongue means are provided for releasably coupling the tongue means to the supporting means to allow the bed means to be tilted when released. Ramp means are hingedly coupled to the supporting means for loading and unloading a wheel supported load, with the ramp means including tilt limiting means for engaging a loading surface and limiting the slope of tilt of the bed means in a manner such that the ramp means and bed means are substantially aligned when loading or unloading a wheel supported load. The side structural means includes means for releasably holding slidably adjustable tie down means for tying down a load. The side structural means can further include a mounting means for adjustably mounting a wheel assembly at any desired position along the length of the side structural means. Auxiliary fender mounting means can be coupled to the side structural means for mounting an associated fender in a desired position along the side structural means. A height adapting means is provided for cooperation with the tongue means to establish a predetermined height adjustment for an associated hitch with respect to a towing vehicle.